Underwater craft



April 1961 J. D. ROBINSON, JR 2,981,073

UNDERWATER CRAFT Filed July 27. 1956 IN VEN TOR. J/QCK D. ROB/NSOMJEFIG. I TM ZW F/ 7' TOPNE Y UNDERWATER CRAFT Jack D. Robinson, Jr.,Norwalk, Conn., assign'or to American Machine and Foundry Company, acorporation of New Jersey Filed July 27; B56, Ser. No. 609,603

6 Claims. (CI; 61-69) This :invention' relates "to mobileunderw atercraft and more particularly "to" underwatertelevision apparatus -whichmay be .rernotely'operated and controlled by a cableconnecting theunderwater craft with a remote control station.

Attachment of a control cable 'has' h therto of ten caused instabilityof an underwater television vehicle because the control cable tended tocreate an overturn- "ing torque acting on the underwater vehicle whenthe 1 cable was'dragged behind the craft or when tension was appliedthereto.

1 Underwater craft particularly when operating at great depths havealsosulfered failure because of water seeping into the control andelectrical wiringcompartments and they have had insufiicient mobilityand control over *their. movement: than was desirable.

It is an 'objectof this invention '[OiPIOVldG'TIlCfiI'lS for improvingthe stability .of remotely controlled underwater craftby reducing.overturning movements exerted about the center of resistance-of theveh1cle' caused by tension exerted by acontrol cable.

A further object of this invention is :to provide an underwatertelevision system which will be protected against water seepage;particularly atgreatdepths.

Anotherobject of this invention -is to provide an underwater viewingapparatus which can :beaccurately bodirnent selected to illustrate theinvention progresses. In the accompanyingdrawing, WhlClI11f0I'11l apart-ofthis I specification, like characters wof reference have beenapplied to corresponding parts throughout the several views which makeup the-drawings.

Figure 1 is asideelevation of my'remotely contr'olled underwater craft.

'FiguregZis an endselevationstaken on line.2--2..of Fi re 1.

i igure 3 is a top view taken on line 33 of Figure 1.

In order to prevent the control cable tension from interfering with thestability of the underwater television craft, I have provided .a cableconnection for the underwater craft which will cause any torque exertedby the control cable to always act on the approximate center ofresistance of the vehicle regardless of what angle the cable makes withthe craft, as more fully described hereinbelow. As a result of employingthis cable connection there are no overturning movements exerted on theunderwater vehicle by the cable, which would cause it to tilt becausethe center of resistance is that point around which twisting of the bodysurrounding the point will not occur when the body is moved through thewater.

A bearing ring having a track 12 formed thereon ice is mounted on andsurrounds the upper end of a framework 14. The framework 14 consists ofthree vertical legs '16, 18, and and a cylindrical base 22.

A buoyancy compartment 24 is also connected to the upper end of theframework 14. A ring 26, having a plurality of trolley carriages 28mounted thereon which tracking on track 12, is free to rotate relativeto the track 12.

,The ring 26 has a pair of lugs 27 formed thereon to which are pivotallyconnected the ends of the yoke 30. A cable connection 32 is formed atthe center of the yoke 30 and has a control cable 34 connected thereto.It will be noted that the swing of the yoke 30 is about -the lugs 27 andthat the lugs 27, being connected to ring 26' is free torotate about thetrack 12. Since. the

ring connection 26'and the pivots of the yoke 'travels about the centerof resistance of the entire underwater craft, there is no tendency forthe craft to topple r or tilt, regardless of what angle a pull ordrag isexerted on the underwater craft, by the control cable 34.

The buoyancy compartment 24 contains .the electrical control andoperating components of the underwater craft and is pressurized toprevent waterflseepage. In

order to-providepressure in the buoyancy compartment 24 slightlyexceeding the ambient waterpressure at all times, there is provided anautomatic demand system which-may be'of any suitable design connectedwith the "compressed air bottles 36 from which air is automaticallydrawn whenever it is necessary to increase, the pressure inside thecompartment. 24 to slightly exceed ambient water pressure on the outsideof the tank 24.

In this way there is only a slight variance in the pres- "sure exertedon' the sealing rings'29 and thedistr'ibution cables'38 which passthrough the buoyancy tank, and

{this slight pressure diflerence acts outwardly to positively preventwater seepage into the buoyancy tank.

'Underwater forward propulsion and steering is provided by' two variablefrequency free flooding motors 40 and 42' which rotatetheir respectivepropellers 44 and-"46'to move the. craft horizontally through the water.

'The windings'of the free flooding induction motors 40 and &2 .are"encapsuled in a suitable epoxy resin to se'al'these components. fromwater. "may-be employed "where ever water enters the motor to Suitablescreens keep out foreign material which might have an abrasive effect onthe resin.

Avariable frequency supply of current for each motor 'is controlled fromthe remote control station to steer,

drive, and control the apparatus underwater to thereby control the speed.and direction of propulsion of said craft underwater. It will beappreciated that .a conor a variable speed'motor described above.

.TheanIgle of pitch-would in such event be controlled from the remotecontrol station to steer, drive, and control the apparatus when underwater at the speed desired.

In order to provide up and down propulsion for the underwater craftthere is provided a central water passageway 48 extending up and downthrough the buoyancy tank 24. At the bottom of this up and downpassageway 48 is mounted a motor-driven propeller 50 which motor is of adesign similar to free-flooding motors 40 and 42- Due to the verticalwater passageway 48 extending through the center of the buoyancy tank 24cavitation is prevented when the propeller 50 is operated.

A flowmeter 51 is mounted in front of the underwater craft to determinethe velocity of movement of the craft to facilitate the exercise ofcontrol over said movement by an operator in the remote station.

In the lower portion of the underwater craft suitable apparatus such aslights 52 and a television camera 54 may be mounted to facilitate makingunderwatervobservations. It will also be appreciated that photographicequipment for taking still pictures can be mounted within the lowerportion of the underwater craft which would be operated in a mannersimilar to the television camera. Suitable elevating means 56 are alsoprovided for raising and lowering said lights 52 and television camera54 relative to the framework 14 to enable close and exact observationsto be made underwater.

From the foregoing description it will be apparent that I have providedan underwater craft which may be freely directed underwater forobservation purposes. Also by connecting the control cables to theunderwater craft so that they act on the craft through its center ofresistance, there is no tendency to tilt the craft which would interferewith its use in observing underwater.

The underwater craft I have shown and described is of slightly lessdisplacement than water so that it will barely float, and by driving thecentral propeller the craft may be easily pulled downwardly andsubmerged.

The invention hereinabove described may be varied in construction withinthe scope of the claims, for the particular device selected toillustrate the invention is but one ofmany possible embodiments of thesame. The invention, therefore, is not to be restricted to the precisedetails of the structure shown and described.

What is claimed is:

1. An underwater craft comprising a frame, a buoyant tank mounted onsaid frame, a track mounted around the circumference of the tank at thelower portion thereof, said track being located substantially on ahorizontal plane passing through the center of resistance of the craft,a ring carrying rollers which are engaged within said track, a yokepivotally secured to said ring, a cable connector secured to the centerof said yoke and a control cable connected to said cable connector.

2. An underwater craft comprising a frame, a pressurized buoyant vesselmounted on said frame, a circular track mounted around the circumferenceof said vessel at a point substantially on a horizontal plane passingthrough the center of resistance of said craft, a ring carrying rollersengaged within said track, a free swinging yoke rotatably mounted onsaid ring, cable connecting means secured to the center of said yoke, acontrol cable connected to said cable connecting means, means for movingsaid craft vertically and means for moving said craft horizontally.

3. In combination with a remotely controlledunderwater craft, means forpreventing control cable tension from interferring with the stability ofsaid remotely controlled underwater craft comprising a circular trackmounted on a horizontal plane passing through the center of resistanceof said craft, a ring carrying rollers engaged within said track, a yokepivotally secured to said ring and a cable connector secured to thecenter of said yoke for connecting said control cable.

4. An underwater craft having the combination of elements provided forin claim 3 wherein there is provided a frame, a substantiallycylindrical buoyant pressurized vessel mounted on said frame, saidvessel having an open-ended channel extending vertically therethrough, amotor and a vertical shaft having a propeller mounted in said channelfor moving said craft vertically by forcing water through said channel,variable frequency motors horizontally mounted on opposite sides of saidframe, having shafts extending on a horizontal plane at a tangent to theperiphery of said vessel, a freeswinging yoke rotatable on said frame,and a control cable connected to said vessel and to said yoke forregulating and controlling the operation of said craft.

5. In combination with an underwater craft remotely controlled through acontrol cable, means for preventing tension of said cable frominterfering with the stability of said craft, said means comprising acircular track adapted for mounting on a plane passing through thecenter of resistance of said craft, a ring carrying rollers engagedwithin said track, a yoke pivotally secured to said ring and a cableconnector secured to the center of said yoke for connecting said controlcable to said craft.

6. A remotely controlled underwater craft comprising, in combination, aframe, terminating in a guard stand at its lower end, a pressurizedvessel mounted on said frame, said vessel having an open-ended channelextending vertically therethrough, a motor vertically mounted in saidchannel for vertically moving said craft by forcing water through saidchannel; motors horizontally mounted on opposite sides of said frame,said motors having remotely-controlled propellers with variable pitchblades to steer and horizontally drive said craft; a circular trackmounted around said frame on a plane passing through the center ofresistance of said craft, .a ring carrying rollers engaged with saidtrack, a yoke pivotally secured to said ring, a cable connector securedto the center of said yoke for connecting a control cable; a supply ofcompressed air mounted on said frame and communicating with said'vessel,an automatic demand system intermediate said vessel and said supply ofair to maintain the pressure inside said vessel above ambient pressureoutside said vessel.

References Cited in the file of this patent UNITED STATES PATENTS896,361 Cage Aug. 18, 1908 1,409,690 Eveleth Mar. 14, 1922 2,019,059Sherman Oct. 29, 1935 2,291,940 Babcoke Aug. 4, 1942 2,359,964 BarnettOct. 10, 1944 2,433,971 Adams Jan. 6, 1948 2,519,453 Goodman Aug. 22,1950 2,592,176 Orlin Apr. 8, 1952 2,685,858 Harrison Aug. 10, 1954

